Hardening transplants, dividing perennials, and pruning roses are some
of the many garden tips for this month.

Acclimate greenhouse-grown transplants over the course of a few weeks
before setting them into the garden. Begin by placing them in a sheltered
spot during the day and bringing them in at night. Then gradually increase
their exposure to sun, wind, and cool temperatures. Once they're in the
garden, be prepared to cover them if a late cold snap threatens.

Transplants of snapdragons can be planted outdoors now. They can tolerate
below-freezing temperatures and flower best in cool weather. Plant them
in groupings for the best show. You just can't have too many snapdragons!

It's time to start planting cole crops, such as broccoli, cabbage, and
cauliflower. These crops should be planted about two weeks before your
last frost date, in soil amended with compost. Don't be concerned if the
leaves turn red or purple. It's often
a sign of phosphorus deficiency due to cool soils and will go away
once the soil warms.

Plant small sections of leaf lettuce every two weeks or so, rather than
planting the whole bed at once. That way, you'll have tender, young leaves
to harvest throughout the spring. As spring heads toward summer, choose
non-bolting varieties.

Now is a good time to dig and divide late-blooming perennials, such
as asters and daylilies. If left undivided, the plants become unproductive
and overcrowded. Dig up the clump, and use a sharp spade to create pie-shaped
wedges. Replant these divisions in a full-sun location in well-drained
soil, and water often to keep soil moderately moist.

Cut back dead rose canes to healthy tissue and remove any spindly branches.
Make a slanted cut that angles up toward an outward-facing bud, starting
1/4-inch above the bud. This directs the new canes to grow outward which
improves air circulation in the middle of the plant to reduce risk of diseases
like black spot.

Check apple, cherry, and other fruit trees for nests of tent caterpillars.
They will emerge at the same time the leaves sprout. Blast nests with a
strong spray of water to destroy them, or spray BT (Bacillus thuringiensis)
on them. BT will harm only the caterpillars and not other beneficial insects,
birds, or humans. You'll need a pump sprayer for this job. Use the
correct form of BT, and follow all label directions and precautions.

To reduce watering, incorporate water-absorbing crystals into the potting
mix when you plant. It's hard to add them afterwards. Since clay pots dry
out faster than plastic, use plastic pots set inside clay pots to help
hold in moisture. Grouping pots together also will help reduce moisture
loss.

Make a note of gaps in your spring bulb garden, and plan to plant bulbs
there this fall. By choosing a variety of bulbs, from early-blooming snowdrops
to late-blooming alliums (ornamental onions), you can have a colorful show
for months. Note the bloom times in plant descriptions. For example, Kaufmanniana
tulips bloom early, while single, late tulips wrap up the spring show.

For many more tips, check out the National Gardening Associationís
regional reports (www.garden.org/regional/).